Historical errata for Google Web Toolkit

“take a look behind to curtain” -> “take a look behind the curtain”

The PDF is attractive and easy to read online - but if one wants to print it for offline reading, it is very poorly designed.

While the horizontal layout is acceptable on-screen, it is unwieldy to carry and read when printed. The colors work okay on a computer display but, when printed on a B&W laser printer, the background prints as about a 40% grey which is both wasteful of toner and makes the book far less legible than it would be if the text were on a white background.

(Dave says: the Fridays are optimtimized for on-screen viewer, and are not intended to be printed)

gwt is now also available for macosx.

“2.3 Create scaffolding … (substituting the appropriate
paths for your system)”
How do I determine “appropriate paths for [my] system”. These instructions need a context.
C:\\gwt-projects\\MyProject> projectCreator -eclipse MyProject
‘projectCreator’ is not recognized as an internal or external command, operable program or batch file.
And I have no idea who projectCreator belongs to or where it is!

After struggling with the steps I then read on p 11 “The projectCreator and applicationCreator commands are two shell scripts that are supplied as part of GWT….” That text should preceed the instructions.

C:\\gwt-projects\\MyProject> applicationCreator -eclipse MyProject\\com.xyz.client.MyApp
results in:
Missing required argument ‘className’
Google Web Toolkit 1.2.22 ….

Putting a space before com… fixes that but one can’t tell from the command that there is a space there.

I’m surprised and discouraged to find 2 errata. Did anyone not familiar with GWT test this?

I was a little sceptical paying $8.95 for a book of only 75 pages. Now when I see how little material there is on a page I’m more discouraged. I suggest less blank areas.

The graphic shows MyApplication. But the name is MyApp.

File ! Import ! Existing Projects Into Workspace
On my version of Eclipse this is:
File ! Import ! General ! Existing Projects Into Workspace

C:\\gwt-projects\\MyProject> projectCreator -eclipse MyProject
‘projectCreator’ is not recognized as an internal or external command, operable program or batch file.
That’s because it lives in the parent directory, and no PATH has been set for it. For me to get it to work I changed it to:
C:\\gwt-projects\\MyProject> ..\\projectCreator -eclipse MyProject

The instructions on the web for reporting erratum say “To find out what version you have, look at the copyright page, a few pages in from the front of the book. If it says (say) Second Printing, then here it’ll be P2.0. If there are interim PDF releases in that printing, they’ll be 2.1, 2.2, and so on.)”
I see no such text on the copyright page.

Clicking any of the Download links does nothing.

Why not add a section about the available frameworks.. this would definitely help ppl reinventing the wheel plus projects like mine(rocket-gwt) have many samples which can help when your a newbie.

I have really enjoyed the ability to buy PDF versions along with paper versions of PragProg books. Keeping the PDF on my HD allows me to refer back to it when needed, while I can read through the paper version. I stare at an LCD screen quite enough as it is.

The PDF for this one has a background gray, which does look prettier and is probably easier on the eyes on screen, but which becomes a mess when printed on my laser printer. Because I don’t like to read onscreen I will probably not buy any mpore Fridays, unless the design changes, or there is an option to buy a “printable version”.

In chapter 2 we can read:
2.2 Installing
“Before you start coding you need to install Java, an IDE, and GWT itself. Java 1.4.2+
First you need a copy of Java. Although GWT works with Java 1.4.2 and newer, you might as well get the latest Sun JDK 5.0 or 6.0”
update from the Sun download site.

This sentence suggests that we can use even Java 5 or Java 6 for GWT programming. This is NOT correct. I use GWT 1.3.1 and if I compile my complete code including servlet code(!) with Java 5 I get an "com.google.gwt.user.client.rpc.InvocationException: oot cause

java.lang.UnsupportedClassVersionError: com/siemens/symphonia/systemtest/gwt/junit2mr/server/JUnit2MRServiceImpl (Unsupported major.minor version 49.0)
That means the Java 5 serlet code is not compatible with GWT’s Tomcat in hosted mode.
Greetings

Klaus Berg

Germany

I would suggest describing creating the scaffolding in IntelliJ Idea, too. It’s very popular IDE among Java developers, and should be supported more in the book.

It would be very helpful to have chapters about REAL programming with GWT. I’m an experienced Swing programmer and I’m looking forward to see how to write a real web app with GWT, i.e., logon to a web app, how to use menu bars with menus, even with menus disabled or to have tables that provide support for row selection, the use of CSS together with GWT, etc. All these non trivial things. But on the server side there is still room for talking about the important role of “setServiceEntryPoint” and its relationship to the GWT module XML spec and the servlet path, what to do if we have more than one servlet, etc.

C:\\gwt-projects\\MyProject> projectCreator -eclipse MyProject
Created directory C:\\gwt-projects\\MyProject\\src
Created directory C:\\gwt-projects\\MyProject\\test <== Test directory is also created - PMG
Created file C:\\gwt-projects\\MyProject\\.project
Created file C:\\gwt-projects\\MyProject\\.classpath

C:\\gwt-projects\\MyProject>applicationCreator -eclipse MyProject\\
[there’s supposed to be a space here but you can’t see it]com.xyz.client.MyApp

1) There should be a space between MyProject\\ and com.xyz.client.MyApp, but the space is rendered invisible by the line break. Without the space the classname is not available to the applicationCreator script and an error is generated. The command should look like this prior to #2 below:

applicationCreator -eclipse MyProject\\ com.xyz.client.MyApp

2) Use of a backslash after MyProject\\ renders Eclipse unable to debug the Java source. I suggest running applicationCreator in the desired folder without using the backslash, otherwise Eclipse bitches about \\ being an inappropriate character in Java code as parsed for debug. If you are savvy enough to remove the \\ then the debugger cranks up properly.

Please clean up these initial glitches. It’s enough to be fresh to the topic without having to troubleshoot format problems and technical glitches. I’ve written enough documentation to know that even when you’re absolutely sure you’ve got things right, you missed something.

You missed something. Otherwise, good job so far, although I am confused by the assumption about Eclipse expertise. I’m learning, but give us newbies a break with Eclipse and hold our hands, at least during the first section.

This is a suggestion for anyone else having problems using the Run -> Debug… feature of eclipse.

From section 2.4 - ‘Running and Debugging’ subsection titled ‘Running Inside Eclipse’ on Page 9 of my pdf version - 2006-11-28 P1.1.

fyi - I’m on WinXP; Eclipse 3.1.2; gwt-windows-1.2.22

I had the problem by which Eclipse could Run in hosted mode but not Debug. I kept getting an error to the effect ‘source not found’. I tried several things and failed including the suggestion on this erratum already - remove the backslash following MyProject\\ in the applicationCreator command. What did work for me? Switching my workspace so that this little project was exclusive to that workspace. So, it seems that projects besides this one from the original workspace were somehow corrupting the Debug process for this little test project.

I’m a relative newbie to Eclipse, about 6 months now, so I can’t be sure of the cause but I now know at least one solution :).

While I have found your PDF of the Google Web Toolkit a fairly useful item, there is one aspect that drives me a little mad.

It would be very helpful if you included the imported classes into your examples. For example, I am currently working on building an RPC call but I do not have the class loaded that allows me access the GWT object. So now I have go off once again and dig though the jar files to locate the correct class that needs to be imported.

Thanks……

on page 15 section 3.1, first paragraph under the header ‘Hosted Mode’ it states you can find figure 2.1 on page 8, but it is on page 12 in the current PDF.

in section 3.2, on page 18 of the current PDF, paragraph two: consider asking the reader to choose one of the aforementioned ways to compile and implement. Otherwise on page 20, section 3.4 in the first paragraph, the reader will not have or be able to find the referred to ‘www’ directory.

no page 22

book text has view:
—————————————————
For example, the Java method:
long f (int n, String s, int[] arr);
has the following type signature:
(ILjava/lang/String;[I)
—————————————————

mistake in omitting semicolon in type signature.
correct case:
—————————————————
For example, the Java method:
long f (int n, String s, int[] arr);
has the following type signature:
(I;Ljava/lang/String;[I)
—————————————————

Under “Miscellaneous”, column “Expression”, “x|y” / “Either x or y”

The pipe character “|” is now shown in the monospaced font but rather as if it were part of the text.